Antibacterial activities of biologically synthesized silver nanoparticles from <i>Alcalypha wilkesenia</i> coated with some antibiotics

Abstract

Silver nanoparticles and Acalypha wilkesiana have been shown through several lines of evidence to possess antimicrobial properties. Their activities, however, have been hampered by one or more problems ranging from poor to slow absorption, cellular degradation, development of antimicrobial resistance and unwanted oxidation in the case of the Nanoparticles. Antibiotic resistance genes have also been on a constant increase recently. This research was carried out to determine the level of efficacy of the combined complex of antibiotics coated with biologically synthesized silver Nanoparticles compared to the orthodox antibiotics individually. The silver Nanoparticles were most active on Klebsiella. pneumoniae (21mm), equal for Escherichia coli and Staphylococcus aureus (14mm) and least for P. aeroginosa (13mm). The activity of the complex on S. aureus was notably highest with the gentamycin (17mm) complex, then ofloxacin (13mm) and finally ampicillin (12mm). That of Pseudomonas aeroginosa ranged from ofloxacin (17mm) to gentamycin (16mm) and then ampicillin (14mm), while that of Escherichia coli was from gentamycin (19mm), ofloxacin (15mm) and then ampicillin (13mm). The activity of the gentamycin (18mm) and ampicillin (18mm) complexes for Klebsiella pneumoniae were found to be equal and a bit higher than that of the ampicillin (11mm) complex. The minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of the selected organisms against the antibiotic complexes carried out between 2.5mg/L to 25mg/L showed no growth in all the samples. There is a need for further research to explore the pharmacokinetics and dynamics of biologically synthesized nanoparticles.